/*
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import DeltaCoder from './DeltaCoder'

export default class DeltaDecoder extends DeltaCoder {
    constructor(distance: number) {
        super(distance);
    }

    public decode(buf: Int8Array, off: number, len: number): void {
        let end: number = off + len;

        for (let i: number = off; i < end; ++i) {
            buf[i] += this.history[(this.distance + this.pos) & 255];
            this.history[this.pos-- & 255] = buf[i];
        }

    }
}
